AP BIO CHAP 4 UNIT 1

Overview: Carbon: The Backbone of Life

• Although cells are 70–95% water, the rest consists mostly of carbon-based compounds

• Carbon is unparalleled in its ability to form large, complex, and diverse molecules

• Proteins, DNA, carbohydrates, and other molecules that distinguish living matter are all composed of carbon compounds

Concept 4.1: Organic chemistry is the study of carbon compounds

Organic chemistry is the study of compounds that contain carbon

• Organic compounds range from simple molecules to colossal ones

• Most organic compounds contain hydrogen atoms in addition to carbon atoms

Hydrocarbons are organic molecules consisting of only carbon and hydrogen

• Many organic molecules, such as fats, have hydrocarbon components

• Hydrocarbons can undergo reactions that release a large amount of energy

Functional groups are the components of organic molecules that are most commonly involved in chemical reactions

• The number and arrangement of functional groups give each molecule its unique properties 

  • The seven functional groups that are most important in the chemistry of life:

    • Hydroxyl group

    • Carbonyl group

    • Carboxyl group

    • Amino group

    • Sulfhydryl group

    • Phosphate group

    • Methyl group

ATP: An Important Source of Energy for Cellular Processes

• One phosphate molecule, adenosine triphosphate (ATP), is the primary energy-transferring molecule in the cell 

• ATP consists of an organic molecule called ‘adenosine’ attached to a string of three phosphate groups

• The versatility of carbon makes possible the great diversity of organic molecules

• Variation at the molecular level lies at the foundation of all biological diversity